My Life is Turning to Crap

Well........ what do you do if you are still seeing that chicks number come up on your husbands phone? He says that he told her not to text anymore......... but that still has not stopped her. He won't just be mean and tell her off. He won't tell her that she is ruining his marrage.......... I don't want to sound selfish, but would it be too much to ask for him to change his number or block hers. He thinks that it is too much to ask. I guess I am just gonna be stuck in a unhappy marrage for the next 2 years just so I can finish school. I am gonna have to start making an exit strategy!! Any Ideas???